Supply of a predetermined physiological salt solution or liquid medicine or the like to the body of a patient is conventionally administered employing a plurality of transfusion tubes, the operation performed in such cases being based on communication and cutoff of these transfusion tubes employing a liquid coinjector. These liquid coinjectors comprise three branch tubes. The liquid coinjector is configured to comprise a chamber that communicates with the three branch tubes and a valve body that rotates within the chamber as a result of the operation of an operating part, communication and cutoff between desired branch tubes being made possible by operation of the operating part to rotate the valve body.
However, in the liquid coinjector described above, the operating part protrudes from the circumferential surface of the chamber and, as a result, the tube members and so on connected to the branch tube sometimes become entwined on the operating part or come into contact with the body of the patient causing the operating part to rotate. For this reason, a liquid coinjector with a cylindrically-formed chamber in which, by movement of the operating part in the direction around the axis of the chamber to afford communication and cutoff between a predetermined branch tube and chamber, the flow passage of a branch tube can be switched without need for the operating part to protrude from the circumferential surface of the chamber has been developed (for example, see Japanese Laid-open Patent Application No. S62-172962). This liquid coinjector is configured by provision of two branch tubes about the circumferential surface of a substantially cylinder-shaped chamber, the two branch tubes being able to be opened and closed by rotation of the valve body in the direction around the axis of the chamber.
However, this liquid coinjector comprises only two branch tubes, and communication and cutoff of these two branch tubes alone is performed. Accordingly, this liquid coinjector cannot be used to link a plurality of transfusion tubes and so on as employed in medical treatments and facilitate communication and cutoff between these transfusion tubes. An additional problem inherent to this liquid coinjector pertains to the rotational operation of the valve body to afford communication and cutoff between the two branch tubes which is difficult to implement.
With the foregoing conditions in mind, it is an object of the present invention to provide an improved liquid coinjector.